While doing my FPV Zephyr build, I realized that there was no "Manual" on how to do the build. While Chris Klick from Ritewing did a great job posting videos, I thought a written step-by-step guide, with links to his videos and other posts, would be helpful. While researching my own build, I read many posts of people putting spars in the wrong places (all spars on the top of the wing!?), putting batteries far back and away from the wing joiner line, etc. One mistake like that can ruin your Zephyr. Many Zephyr build posts you'll find on rcgroups are also very outdated. The construction of the Zephyr has changed over the past year: no more riteweave, for example. In the manual below, I am providing a build sequence that I think is most practical and not obvious.

A few general points before we get started:

----NEWS: Trappy, one of the leading FPV innovators that was banned from RCG, is willing to answer your manual/build questions on a "Trappy-Suported" version of this manual on the new FPV focused forum site "FPVLabs".
----

Why build a Zephyr for FPV as described below? Because it's the plane used to shoot this recent FPV video by TeamBlackSheep. If this video does not make you want to order your Zephyr today and start building, you may want to consider a different plane, or different hobby

Watch ALL Build Videos from Chris/Ritewing multiple times: http://www.youtube.com/user/TheRitewing1
Chris goes quick and does his build in his own sequence. My sequence of steps is slightly different, but I think should help prevent you from cutting things into the wrong place.

Building a Zephyr for FPV is not quick nor simple -- it's a full blown kit building process that will take you considerable time, effort, and money (expect to pay $2,000USD+ for the plane and FPV gear). If you rush your build, you can do it in 12 hours. If you take your time you can easily spend 40+ hours. The researching/sourcing/buying of all the gear you need for the plane, FPV specific gear on the plane and on the ground, will take you time and effort. If this is your first entry into RC planes, I suggest you start with an EPP ARF build first to get used to the process of building and flying.

Accolades

Quote:

"Spot on, good manual" -- Trappy, TeamBlackSheep January 31st, 2011

"A 'must read' to get your Zephyr built for best performance" -- Chris Klick, Ritewing, February 23rd, 2011

Thanks to...

Chris Klick / Ritewing for his endless wisdom and ideas for building the best flying wing out there. Check out the many Zephyr threads in the Ritewing rcgroup area, just realize that much of what's posted there is outdated.

Trappy and RiskyD for paving the way of how to get the most out of a Zephyr for FPV flying. If you're scared off doing the build after looking at this manual, you can now buy a Zephyr from Team Black Sheep that is almost ready to fly and includes many of the needed FPV gear components and a wiring harness.

Partners

ImmersionRC -- proven FPV equipment that is easy to use, powerful, and well integrated. If you watch Zephyr FPV videos that make you go "Wow", chances are it's using ImmersionRC gear.

First, get your FPV specific kit from www.ritewingrc.com -- the FPV specific kit is NOT listed on the site, so no need to look for it. You have to contact Chris from ritewingrc to order one. You can find Chris' posts under user Klique. The Zephyr FPV kit is available in a few different sizes and comes as pointy nose or a wider blunt nose in each size:

Many of the posts you'll find only discuss 54" builds. A 60" build has the same build process, but the exact CG placement may be a little different. Specify what size and nose type you want when you order.

The kit from Ritewing comes with:

The wing EPP pieces ("wing-cores")

Wing-beds: The wing-cores are packaged in the foam that they were cut out off. Do not throw these out! You will use them during your build. They will ensure that your wing is lying flat/straight on your building table.

4 'external' wing spars (light/thinner fiberglass). These go on the top and bottom of the wing. See below.

Keep in mind that the kit may come with different gear -- the outside spars may be black as well, so you'll need to make sure you know which spars are the internal ones and which are for the top/bottom.

Things you will need and that do NOT come with the kit. You will be spending a significant portion of your build time on procuring the things on this list. This list is one of the most important parts of this manual:

Laminate to cover the wing and elevons. Chris/Ritewing sells a supply of laminate for the build that includes a few different strengths for various pieces of the wing. If you want, learn more about laminate.

2 Push-rods and Clevises: Amazon (these rods are used if you are running your rods on the outside and not inside the wing). Depending on your the rods you choose, you may also need to buy extra push-rod clevises.

2 Control Horns: Sullivan Steel Horns or use the strongest control horns you can find. Don't use plastic control-horns as they can break too easily.

1 folding prop and prop mount. The prop mount is the middle piece that holds the folding prop halves and attaches to your motor's shaft. It should be between 37 and 40mm. You will want to find a unit that is described as something like 40/5/8 if your motor has a 5mm shaft. The first number is the distance of the two prop halves. The higher this number the longer your overall prop will be. The second number is the shaft diameter of your motor. The last number is the width of the pro hinge that attaches to the middle piece -- 8mm is most typical for the size prop you'll be using for your Zephyr. A typical motor for a 54 or 60" FPV Zephyr, the Hacker A30-10L, has a 5mm shaft.A large selection of middle pieces from Europe or Icare-RC in the USA.

2 'prop stops' so that the prop does not fold in & out too far (Your plane will crash or explode without it. Make sure you have it and that it works 100%). Order one at http://www.fpvmanuals.com/prop-stop.

2.) Decide on where to put the motor
Depending on how heavy your build will be, you have to decide on where to put the motor. You can go all the way to the TE if you use large/heavy batteries and plan on using a GoPro (100g by itself). If your build uses lighter batteries, move the motor up to the internal spar. Chris suggests to move the motor to the spar, as you'll see in his video. Just realize, that's not the only place to put it. For a build that puts the motor on the TE, see this thread.

3.) Cut in the main equipment bay
Cutting in the main equipment bay is a good next step. Leave yourself room between the LE and your bay for the batteries (assuming you use 2 batteries) which will be cut in last -- to get the CG right at the end of the process. The more room you have between the LE and your bay the easier it will be for you to move the batteries up or back to get the CG right. If your bay is so close to the LE that the batteries barely fit in front of it, there is no way to tweak the CG. Also, don't go too far to the TE as the internal spars will get in the way. Do not cut your main equipment bay over the internal spars as you will hit them as you dig into the foam.Video: how deep to cut the baysVideo: placement

4.) Place the wing spars
The 4 fiberglas spars are next. They go on the outside of the wing and are installed parallell to the LE. Two on top and 2 on the bottom of the wing. Now that you have cut in your main equipment bay already, you can move the spars to the right place without having them in the way later. There are lots of discussions on which glue to use: gorilla (which foams up), CA, etc. I think CA is the easiest method. Gorilla gets messy. Here is a good video on how to do it (but use a straight edge instead of the spar to guide your knife).

5.) Place the rest of your equipment except batteries
Place servos, Video TX, ESC, ect. As you have the spars in place, the servos now are forced into one of 2 possible positions. Either A) in between the LE and the wing spar OR B) behind the wing spar closer to the TE. If you use heavy batteries, the sequence for placement is (from the nose of the plane):
LE
Batteries
Spar
Wire Channels (for RC RX UHF and Video TX)
Servos

For a lighter build, you would want to put the servos in between the LE and wing spar to move them up to the LE. That's how Chris does it in his video.

When creating a cavity in the foam for your servos, decide beforehand if you'll be using push-rods that are running above the foam or through the foam (you'll need different push-rods for each method). If you run your rods outside of the foam, your servos should not go too deep into the EPP so that your rods easily run above the wing.

6.) Painting and Lamination
A lot of questions revolve around the topics of "riteweave" and "laminate". The "riteweave" method is the older method, which applied a fiberglas mesh over the wing with 3M 90 glue. The result was a strong wing, but very heavy. The new method is to use laminate and to use riteweave or fiberglass only in specific, weak places such as the LE, over the servos, etc. Laminate is a clear film that is ironed onto the wing.

A new method for painting that creates a very smooth finish (1/31/2011):
- Start by sanding your wing (not by applying 3M 90!)
- Apply a coat of Lightweight Vinyl/Latex Spackling on the EPP
- Sand it down to make it smooth
- apply some Loctite 200 Spray Adhesive to the top of the bay lids (coroplast) to give the paint something to stick to
- Paint with spray paint
- Now use Loctite 200 Spray Adhesive instead of 3M 90 over the entire wing, on top of the paint. Let it dry for at least a day. The benefits of this glue is that it does not 'weave out' like the 3M 90 does.

A word on using 3M 77: Do not use 3M 77 as your lamination undercoat. 3M 77 does not dry fully, making it difficult to work with when applying the laminate. Even worse, 3M 77 will releas the laminate when it gets warm.

Paint selection

You can use basic spray paint. As you will cover the wing and elevons with shiny laminate, you can use matt paint. Below, an elevon painted with matt white spray paint and then laminated with 3mil laminate:

Lamination
If you buy laminate from Chris/Ritewing for your build, you will get 3 different thicknesses (mil = thousands of an inch):

- 3mil for top of wing and elevons
- 5mil for the bottom of the wing (you can also use 3mil here to keep it light)
- 10mil to create a 'skid plate' on the bottom of the wing in the center section that hits the ground first when you land. You apply this on top of the 3mil or 5mil laminate you've used on the bottom of the wing.

Great video on how to apply the laminate. Keep in mind that you do not need to apply the tape to the elevons on your Zeph build. Fast forward to 1:40" as the rest is not applicable to the Zeph build (this video is not showing a Zeph, but how to apply the lam on an EPP wing).

7.) Trim and attach the elevons
1.) Trim the elevons as seen in the video to improve flight characteristics
2.) Paint the elevons (optional)
3.) Laminate the elevons
4.) Attach them to the TE with 3M Scotch Mailing / Storage Tape (see video)

8.) Cutting in the battery bays and balancing / CG optimization
Lamination will affect your CG by moving the CG back towards the TE, so cutting in the batteries last is a great way to finding the right CG. The CG is normally 10.5" from the nose of the plane, but I read reports that people found this to make the plane tail heavy. The CG is affected by where you put your motor, main equipment bay location, how much and which gear you use, etc. The single heaviest item in your build are likely the batteries -- most FPV Zephyrs use 2 batteries in parallel. You want your batteries to be as close to the wing joiner line as possible. Batteries that are far away from the wing joiner line will impact your Zephyr's ability to perform quick turns. Take a look at the pictures for an effective way to place the batteries. If you use heavy batteries (700g or more in total), it's possible that your Zephyr will still be nose heavy even if you place your motor on the TE.

9.) Affix the winglets
The winglets go on the wing tips. They stick out equal amounts on the top and bottom of the wing and are aligned with the LE and run horizontal. As the winglets always hit the ground when landing (as they stick out on the bottom), they can get damaged over time. Before you attach your winglets, trace them on a board of 4 mm coroplast (find it in Home Depot's lumber department). If your winglets ever get messed up, simply cut out new ones to replace them.

You can connect the winglets permanently or make them removable.

Permanent

First, lightly affix your winglets to the wingtip on each side with a quick/thin bead of hot glue. This is just to hold your winglets in place firmly while we move on to the next step. Next, use "Goop" glue to run a bead of glue around the wingtip where it meets the winglet and then run your finger around it to smooth it out. Similar process to caulking a bathtub. The Goop glue will create a strong bond between the laminate and the coroplast winglet. If the winglet is ever damaged, run a razor blade around to cut the Goop joint and replace the winglet. Use Goop -- don't use CA (as it will pop off the coroplast on impact), Gorilla, etc.

Removable

With the removable method in the event of a crash, the winglets will rip off cleanly rather than damage your wingtip or get tangled in trees. You use epoxy to glue commercial strength velcro onto the wingtip. If you have a strong velcro that has an adhesive back, you can stick that directly onto the coroplast winglet. On the wingtip, you should first epoxi or PU glue a solid base such as a thin carbon board, some balsa, or fiberglass that will firmly attach to the wingtip. You then epoxy the velcro onto that base. When the wingtip and winglet are connected, they should form a very strong bond which will only release in a real crash, but not on every landing or gust of wind. You do not want to have a winglet come off at the wrong time, so make it as strong a connection as possible using the best velcro you can find.

great guide! Been wanting to do this myself after looking through all the Zephyr threads on RC groups.

Some things I found (an please anybody correct me if I understood something wrong): Draw the center line on the wingcores first ( on the part where you will glue them together later) from LE to TE. This gives you a line to measure out your COG. I also use it to mark top and bottom of the thickest part of the profile and that's where I put in my fibreglass top and bottom spars: This way I can make sure the are perpendicular for maximum strength.

Also one guy glued in a piece of string at the COG when he glued together the wingcores . This way he only needed to pick up the string to see how the wing would balance during the building process.

If you're new to the laminating thing you can laminate in 4 parts so reduce chance of the wing warping in the process:

"Cut film for top in four pieces then use iron w out a sock, start with temp low at 225 F or so and work your way up. Use wingbeds to lay wings in to keep them strait and tru ,then over lap the lam film joints 1/4 inch.
After you do a few wings you will be able to do the wing in less pieces.
Its easier to do more at first so you dont distort the wing learning.."

I think Chris does laminate the ailerons as well, I will do too. Just no need to do the first spray of 3M90 prior to painting. (so paint-3M90-laminate)

To glue in the motor mount you can use hot glue.

great thread and I'll be watching for sure!

Maarten (still waiting for the last parts to arrive before I can start the build of my Zephyr!)